Many crude oils contain surface-active materials that cause foam problems during distillation and prevent distillation from taking place. Often anti-foam agents such as ethylene glycol, propylene glycol, polyols, and C.sub.6 -C.sub.20 straight chain alcohols are incapable of stopping the foaming to allow distillations to proceed. This is especially true when ionic surface-active substances cause the foaming.
Surfactants have the reputation of being foam-causing agents, although some surfactants have been described as having low foaming characteristics. U.S. Pat. No. 3,684,736 describes a low foaming surface-active composition. This cationic-anionic surfactant complex is used in an aqueous environment where surfactant characteristics are desired. A similar disclosure is found in U.S. Pat. No. 3,817,871. This patent teaches that the combination of certain cationic and anionic surfactants will yield another surfactant with superior surfactant characteristics which is suitable for solvent/water systems.
Ionic surface-active substances are frequently found in hydrocarbons which must be distilled. Such substances frequently cause foaming which prevents distillation from occurring. It would be advantageous to eliminate the foaming caused by such surface-active substances so that distillation could proceed.
Surprisingly, it has been discovered that surfactants, known for causing foaming, can be used to eliminate foam. It is an object of the instant invention to eliminate foaming problems caused by ionic surface-active materials in hydrocarbon distillations. Other objects will become apparent to those skilled in the art as this discussion proceeds.